1. Field of the Invention
The present invention relates to a leak detecting method for vessels such as pressure vessels and hermetically sealed vessels and more particularly to a leak detecting method for vessels which employs sulfur hexafluoride as a tracer gas to utilize the absorption of a carbon dioxide gas P(16)-line laser light by the tracer gas.
2. Description of the Prior Art
Included among conventional leak detecting methods for vessels represented for example by pressure vessels and hermetically sealed vessels is a method so designed that as for example, a Freon gas is sealed into a vessel and a halogen detector is used to detect any leakage from the vessel.
There is known another method so designed that the whole vessel is placed within a high vacuum vessel and a helium gas is sealed into the vessel, thereby detecting any leakage from the vessel by use of a helium detector.
With the conventional leak detecting methods for vessels, the former prior art or the method of using a Freon gas has the disadvantage of destroying the terrestrial environment, and thus its use will be limited or inhibited in the future.
Also, the method of using a helium gas is disadvantageous in that since the vessel is placed within the high vacuum vessel, a test equipment is considerably increased in size and moreover it is difficult to reduce the locations of any leaks.